Device for making lap joints for plastic film and the like

ABSTRACT

A flexible channel has inturned overhanging side edges overhanging the base either by the same or different amounts. A flexible tape has beads formed along each edge and these beads engage under the side edges of the channel when installed. Plastic film or the like is laid over the channel whereupon the tape or locking strip is engaged over the film and forced into engagement within the channel. If the channel with different dimensions is used, the tape or locking strip is first engaged under the widest edge and then snapped into engagement under the narrowest edge. When tension is placed on the film in a direction away from the widest edge, the tape is pulled into further engagement under the narrow edge which prevents the tape or locking strip from disengaging from the channel. When the pull on the tape is from either or both directions, the channel with equal dimensioned edges is used and a tool is then required to buckle the tape or locking strip prior to its being engaged under the side edges of the channel. In both instances the tape or locking strip takes up a concave configuration relative to the base of the channel due to the fact that the beads on the edges of the tape are on the underside and engage the base of the channel with the plastic film sandwiched therebetween.

United States Patent [191 Curry DEVICE FOR MAKING LAP JOINTS FOR PLASTIC FILM AND THE LIKE [76] Inventor: Walter .1. Curry, 337 Roberta St.,

Winnipeg, Canada [22] Filed: Oct. 16, 1973 [21] Appl. No.: 406,786

Related U.S. Application Data [63] Continuationin-part of Ser. No. 379,815, July 16,

1973, abandoned.

[52] 05. Cl. 24/243 K [51] Int. Cl A4411 21/00 [58] Field of Search 24/243 K, 243 M, 243 N, 24/725 [56] References Cited UNITED STATES PATENTS 1,484,382 2/1924 Allitt v 24/243 M 2,164,414 7/1939 Long 24/243 K UX 3,141,221 7/1964 Faulls........ 24/243 M X 3,225,407 12/1965 Daniels 24/243 K 3,384,938 5/1968 O'Connor 24/243 K 3,527,284 9/1970 Nelson et a1 24/243 N X 3,792,510 2/1974 Evett 24/243 K 3,805,873 4/1974 Bloomfield 24/243 K X FOREIGN PATENTS OR APPLICATIONS 1,245,940 10/1960 France 24/243 K [4 1 July 8,1975

Primary ExaminerDonald A. Griffin Attorney, Agent, or FirmStanley G. Ade

[5 7 ABSTRACT A flexible channel has inturned overhanging side edges overhanging the base either by the same or different amounts. A flexible tape has beads formed along each edge and these beads engage under the side edges of the channel when installed. Plastic film or the like is laid over the channel whereupon the tape or locking strip is engaged over the film and forced into engagement within the channel. If the channel with different dimensions is used, the tape or locking strip is first engaged under the widest edge and then snapped into engagement under the narrowest edge. When tension is placed on the film in a direction away from the widest edge, the tape is pulled into further engagement under the narrow edge which prevents the tape or locking strip from disengaging from the channel. When the pull on the tape is from either or both directions, the channel with equal dimensioned edges is used and a tool is then required to buckle the tape or locking strip prior to its being engaged under the side edges of the channel. In both instances the tape or locking strip takes up a concave configuration relative to the base of the channel due to the fact that the beads on the edges of the tape are on the underside and engage the base of the channel with the plastic film sandwiched therebetween.

6 Claims, 12 Drawing Figures PATEMLTEDJUL a 1915 3 8 93,212

SHEET 2 DEVICE FOR MAKING LAP JOINTS FOR PLASTIC FILM AND THE LIKE BACKGROUND OF THE INVENTION This invention relates to new and useful improve ments in fastening systems for plastic film and constitutes a continuation-in-part application to my application Ser. No. 379,8I5, filed July 16th, 1973 and now abandoned. This application constitutes an improvement over my U.S. Pat. No. 3,505,725, issued Apr. 14th, 1970.

The above identified United States Patent shows a machine for installing a planar locking strip within a flexible channel having overhanging side walls of equal dimension.

The device and method described in the patent while satisfactory for some circumstances, provides a lap joint which is not always satisfactory for other conditions. This is because the locking strip lies flat when installed and, under certain conditions of tension upon the film held thereby, can become disengaged.

Furthermore there are many installations where the pull on the film is in one direction so that the channel can be formulated which permits the locking strip to be installed without the use of the special tool illustrated in that patent.

SUMMARY OF THE INVENTION The present invention includes a flexible elongated channel having overhanging side walls either of the same dimension or different dimensions with a flexible locking strip having a novel configuration.

One embodiment of the locking strip includes longitudinally extending beads formed along each edge of the locking strip upon one side thereof which are adapted to face downwardly towards the base of the channel when installed thus permitting the web of the locking strip to be forced into a downwardly curved concavoconvex relationship relative to the base of the channel thus preventing displacement of the locking strip.

Another embodiment includes a relatively simple tool for installing one edge of the locking strip after the other edge has been engaged under one overhanging side edge of the channel and a further invention shows two other methods of facilitating the installation of the locking strip particularly when used with a channel having equally dimensioned overhanging edges.

Another object of the invention is to provide a device of the character herewithin described which is particularly suitable for use in attaching flexible material or the like to a retaining or locking strip fixed to a supporting surface and is particularly suitable for use in upholstery work or the like.

Still another object of the invention is therefore to provide a device of the character herewithin described which permits the specific form of channel to be chosen depending upon the pull on the film being held by the locking strip engaging the channel.

A still further object of the invention is to provide a device of the character herewithin described which is simple in construction, economical in manufacture and otherwise well suited to the purpose for which it is designed.

With the foregoing objects in view, and other such objects and advantages as will become apparent to those skilled in the art to which this invention relates as this specification proceeds, my invention consists essentially in the arrangement and construction of parts all as hereinafter more particularly described. reference being bad to the accompanying drawings in which:

DESCRIPTION OF THE DRAWINGS FIG. 1 shows a partially schematic end view of both embodiments of the channel with a sheet of film being held thereby.

FIG. 2 is an end view of one embodiment of the channel showing the locking strip just prior to its being snapped into position.

FIG. 3 is a view similar to FIG. 2 but showing the relatively simple tool which may be used to facilitate the engagement of the edge of the locking strip within the channel.

FIG. 4 is a view similar to FIG. 3 but showing the relatively simple tool in the act of engaging the edge of the locking strip within one embodiment of the channel.

FIG. 5 shows one embodiment of the channel with two sheets of film and the locking strip in position to be engaged within the channel.

FIG. 6 is a view similar to FIG. 5 but showing the locking strip in the channel with the edges of the film being held in overlapping relationship therewithin.

FIG. 7 is a fragmentary isometric view of the locking strip and channel of FIG. 4.

FIG. 8 is an end view showing one embodiment of the device being used for upholstery or similar finishing.

FIG. 9 is an end view of a yet further embodiment of the locking strip per se.

FIG. 10 is an end view partially schematic showing a tool for facilitating the engagement of the locking strip of FIG. 9 within the channel.

FIG. II is a view similar to FIG. II) but showing a different embodiment of the tool.

FIG. 12 is an end view of an alternative embodiment of the channel.

In the drawings like characters of reference indicate corresponding parts in the different figures.

DETAILED DESCRIPTION Proceeding therefore to describe the invention in detail, reference should first be made to FIG. 7 which shows a channel collectively designated 10 preferably made of relatively flexible plastic or similar material and including a planar base 11 and a pair of overhanging side wall portions I2 with the inner longitudinally extending edges 13 being spaced above the base 11 and turned inwardly towards one another as clearly shown.

A locking strip collectively designated 14 is also made of relatively flexible plastic or similar material and extends longitudinally and includes a substantially planar web 15 having longitudinally extending beads 16 formed on each edge of the web and upon the underside thereof with reference to FIG. 7 and these beads normally engage under the overhanging side walls 12 as clearly illustrated in FIG. 7 with plastic film (not illustrated in this view) being sandwiched therebetween.

It will be observed that when the locking strip I4 is engaged within the channel I0 as shown in FIG. 7, the web 15 lies in a concavo-convex relationship with the base 11 of the channel and towards said base, the purpose of which will hereinafter be described.

FIG. 4 shows a similar embodiment of the channel as that shown in FIG. 7 with a sheet of plastic film I7 being sandwiched between the locking strip 14 and the channel 10.

During the installation of the locking strip, the film is first laid within the channel whereupon one side edge of the locking strip, specifically designated 16A, is manually engaged under one overhanging edge of the channel specifically designated 12A.

A relatively simple tool collectively designated 18 may then be used to engage the other side edge 16B of the locking strip under the other overhanging side edge 12B of the channel as clearly illustrated in FIG. 4. This pull includes a handle 19 having a stem 20 extending therefrom and a spindle 21 extending at right angles from the lower end of the stem. A wheel collectively designated 22 is journalled for rotation upon the spindle 21 and this wheel includes a concave rim portion 23 which extends between a relatively wide perimetrical edge 24 and a relatively narrow perimetrical edge 25 as clearly illustrated. This concave rim portion engages the edge portion of the locking strip in wedging relationship with the overhanging edge 13 of the channel and by running the wheel longitudinally along the junction between these parts, the tape is buckled as illustrated so that the bead or edge 16B of the locking strip is engaged under the overhanging edge 12B of the channel.

FIGS. 2 and 3 shows a further embodiment of the channel in which the one overhanging side edge 12A overhangs the base by an amount greater than the other overhanging side edge 12B as clearly illustrated. This permits the film of plastic 17 to be engaged within the channel and manually forced into the wider overhanging side edge 12A by the engagement of the side edge 16A of the locking strip. The web 15 of the locking strip may then be pushed downwardly either by means of a simple tool 18 or by the thumb of the operator so that the other edge 16B is snapped under the overhanging side edge 1213 as clearly shown in FIG. 2 and in FIG. 3.

FIG. I shows a combination of the two embodiments of the channel illustrated in FIGS. 2 and 4 and is usable where a relatively wide area of film I7 is to be secured to a structure. Reference character 26 illustrates supports to which the channels 10 may be secured by means of nails 27 or the equivalent. In this embodiment. the strain upon the film 17 is in the direction of arrows 28 insofar as the two outer channels are concerned and in the direction of arrows 29 insofar as the central channel is concerned.

It will be noted that the outermost channels are similar to the channels illustrated in FIGS. 2 and 3 so that when the strain is applied in the direction of arrows 28, the locking strips are forced outwardly in the direction of arrows 30 so that the side edges 16B are forced into engagement with the outermost overhanging side edges 12B of the channels thus preventing inadvertent disengagement of the locking strips from the channels. In this connection it will be observed that the webs of the these outermost locking strips flexs downwardly towards the bases 1] of the channels once again preventing disengagement of the locking strips from the channels.

The central channel having equal overhanging .42 edges. operates in a similar manner depending ups-n which side of the film has the greatest pull or tensn :1 placed thereon. However as hereinbefore described, this requires a tool such as the tool 18 for installation whereas the outermost channels may be installed without the tool if desired.

FIGS. 5 and 6 show a similar channel 10 as illustrated in FIGS. 2 and 3, being used to form an overlapping junction between the marginal edges of two sheets of film 17A and 17B, the operation of the installation of the locking strip 14 being similar to that hereinbefore described. This enables the structure to be used for joining two sheets of flexible material together.

FIGS. 9, 10 and 11 show a further embodiment particularly having regard to the tool to facilitate the installation of the locking strip within the channel.

In this particular embodiment, the locking strip is illustrated by reference character 14A and is provided with a centrally located longitudinally extending rib 31 upon the upper side of the web 15. This rib is provided with flanges 32 extending upon each side thereof at the upper side of the rib as clearly shown.

Dealing first with the tool shown schematically in FIG. 10, a frame 33 is provided with a maniuplating handle 34 on the upper side thereof. A pair of downwardly extending spindles 35 carry a knurled wheel 36 for rotation substantially in a horizontal plane relative to the frame 33. These knurled wheels incudes the relatively wide knurled upper perimeter 37 and a concave rim 38 narrowing down to the lowermost perimeter 39. The knurled perimetrical rims 37 engage under the flanges 32 of the rib 31 and the spacing of the concave rims forces the tape into the position shown in FIG. 10 thus facilitating the engagement within the channel 10 after the film 17 has been laid over the channel.

In FIG. 11, a further embodiment is shown schematically in which a frame 40 is also provided with a maniuplating handle 41 and spindles 42 depending downwardly to support for rotation, knurled wheels 40'. These wheels are reversed with respect to the wheels 36 shown in FIG. 10 and have relatively wide knurled perimetrical edges 44 which engage under the flanges 32 of the rib 31 and support the locking strip during the installation within the channel 10.

The frame 40 is provided with dependent side plates 45 which carry side wheels 46 for rotation in a substantially vertical plane relative to the frame and at right angles to the aforementioned wheels 44. The spacing of these wheels forces the locking strip into the position clearly illustrated and the convex rear faces 47 of the these wheels act in a wedging relationship with the overhanging side edges 12 of the channel and facilitate the insertion of the buckled locking strip. In this embodiment the plastic film 17 is now shown.

Finally reference should be made to FIG. 8 which shows the device being used to secure flexible material to give a finished appearance on upholstery work or the like.

In this embodiment, the locking strip is designated by reference character 48 and is substantially U-shaped when viewed in end elevation and the locking strip is secured to the supporting surface 49 by means of stapics 50 or the like whereupon the material 51 is engaged over the channel 52 which is then in turn engaged over the edges of the locking strip 48 thus giving idden means of attachment.

ix]. 12 shows an alternative embodiment of the as- "Poly inch is particularly suitable for use with relatively thin film which may tear easily, particularly when the device is used under conditions of low temperatures.

if tolerances are low, and the temperature is low, the material tends to be extremely stiff and the insertion of the locking strip can cause the film to be cut or torn.

The embodiment is similar to those previously discribed so that similar reference characters have been given where appicable.

The overhanging side wall 12A is similar to that hereinbefore described but the other overhanging side wall 12C is modified to overcome the disadvantages mentioned above.

The longitudinally extending edge 13A, in this embodiment, depends downwardly towards the base 11 and is manufactured from a material flexible enough to enable this downwardly extending portion to be in a hinging relationship to the major portion 133.

This means that when the bead 16 of the locking strip 14 is forced into engagement as hereinbefore described, the downwardly depending portion moves outwardly in the direction of arrow 53 thus facilitating the engagement of the bead 16. As soon as the bead 16 passes the lowermost extremity of this downwardly extending portion 13A, the resiliency of the material causes this portion to move back to the original position in the direction opposite to that of arrow 53 thus allowing the engagement of the locking strip even in cold weather, without tearing or cutting the film held thereby.

Since various modifications can be made in my invention as hereinabove described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without departing from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.

What I claim as my invention:

1. Apparatus for holding flexible plastic film in place comprising in combination an elongated flexible channel including a base and a pair of side walls overhanging the side edges of said base, an elongated flexible locking strip detachably engageable under said over hanging side walls, said locking strip including a web having a longitudinal edge on each side thereof, said edges engaging under said overhanging side walls and facing the base of said channel when installed, the associated flexible plastic film being sandwiched between the locking strip and said channel, one of said side walls including a downwardly extending edge portion, said edge portion being substantially flexible and being displaced outwardly when said locking strip is engaged, and moving back to the original position after said locking strip is installed.

2. The apparatus according to claim 1 in which one of said overhanging side walls overhangs said base by an amount greater than the other of said side walls, said downwardly extending edge portion being formed on said other overhanging side wall.

3. Apparatus according to claim 2 which includes a bead formed longitudinally upon each of said edges of said web.

4. The apparatus according to claim 3 in which the web of said locking strip lies in a concavoconvex relationship towards said beads when installed.

5. Apparatus according to claim 1 which includes a bead formed longitudinally upon each of said edges of said web.

6. The apparatus according to claim 5 in which the web of said locking strip lies in a concave-convex relationship towards said beads when installed. 

1. Apparatus for holding flexible plastic film in place comprising in combination an elongated flexible channel including a base and a pair of side walls overhanging the side edges of said base, an elongated flexible locking strip detachably engageable under said over hanging side walls, said locking strip including a web having a longitudinal edge on each side thereof, said edges engaging under said overhanging side walls and facing the base of said channel when installed, the associated flexible plastic film being sandwiched between the locking strip and said channel, one of said side walls including a downwardly extending edge portion, said edge portion being substantially flexible and being displaced outwardly when said locking strip is engaged, and moving back to the original position after said locking strip is installed.
 2. The apparatus according to claim 1 in which one of said overhanging side walls overhangs said base by an amount greater than the other of said side walls, said downwardly extending edge portion being formed on said other overhanging side wall.
 3. Apparatus according to claim 2 which includes a bead formed longitudinally upon each of said edges of said web.
 4. The apparatus according to claim 3 in which the web of said locking strip lies in a concavo-convex relationship towards said beads when installed.
 5. Apparatus according to claim 1 which includes a bead formed longitudinally upon each of said edges of said web.
 6. The apparatus according to claim 5 in which the web of said locking strip lies in a concavo-convex relationship towards said beads when installed. 